And that's why email encryption is such a no brainer
You don't send hugely personal information on postcards; you put it in an envelope. Sure your email is that personal - and that protected? Surely the ISP doesn't read your email and won't just hand it over to someone without telling you? No, no, maybe, yes. In the UK RIPA and other orders say the police can get your email when they want and you'll never know (it's possible but unclear that it might even be an offence for your ISP to tell you they've handed it over). And in the US, an Oregon judge quoted in the WSJ Law blog http://blogs.wsj.com/law/2009/10/29/on-gmail-and-the-constitution/) says no, the Fourth Amendment doesn't keep your email private. The Fourth protects the privacy of your home, but the Internet is not your home and the inbox on your computer is - especially for Webmail like Gmail - actually the server at some other company. By putting email there, you have given up your reasonable expectation of privacy. Obviously, most people don't know this and would probably disagree with it - but it's the law.
Money quote; "Most of the reluctance to apply traditional notions of third party disclosure to the e-mail context seems to stem from a fundamental misunderstanding of the lack of privacy we all have in our e-mails. Some people seem to think that they are as private as letters, phone calls, or journal entries. The blunt fact is, they are not."
So - could we all start encrypting our emails please? It's legal, it's not expensive, it's probably not even that difficult any more - but for some reason we just all can't be bothered. I guess if we're going to flaunt it all on Facebook, email privacy is so 1990s...